Among the first documented Africans in British North America were approximately 20 men and women who arrived at Jamestown, Virginia, in 1619. They were captives, likely from the kingdom of Ndongo in present-day Angola. Privateers had seized them from a slave ship bound for Mexico and traded them in Virginia. The Africans worked the tobacco fields in Jamestown alongside white indentured servants, but it is not clear if they were considered slaves.
At the end of the 18th century, Jefferson and many other Americans believed that stopping the import of enslaved people from Africa and the Caribbean would hasten the end of slavery.
In 1807, three weeks before Britain abolished the Atlantic slave trade, President Jefferson signed a law prohibiting “the importation of slaves into any port or place within the jurisdiction of the United States."